The science of the casino: why the house always wins in the long run |
You’ve probably heard the phrase “the house always wins” when it comes to casino gambling. But what does it actually mean?
After all, people do hit jackpots, and casino games are supposed to be fair – so what guarantees the casino still comes out ahead?
The answer lies in a simple but powerful mathematical idea called “the house edge”: a small, systematic statistical advantage built into every casino game. It’s the invisible force that ensures the numbers will always tilt toward the house in the long run.
So, let’s unpack the science behind that edge: how it’s constructed, and how it plays out over repeated bets.
Roulette looks like one of the fairest games in the casino. A spinning wheel with numbered pockets, half coloured red and half coloured black, and a single ball sent careening around the outside to eventually land in one pocket at random. If you bet the ball will land in a red pocket (or a black one), it feels like a 50–50 gamble.
But the real odds are a little bit different. In most Australian casinos you’ll find 38 pockets on the roulette wheel: 18 red, 18 black, and two “zero” pockets marked 0 and 00. (In Europe roulette wheels have 37 pockets, with only a single 0.)
The zero pockets are what creates the house edge. The casino pays out as if the odds were 50–50 – if you get the colour right, you get back double the amount you bet. But in reality, on a........